It is conventional practice to provide mud or rain flaps behind the wheels of motorized vehicles and in particular behind those of large trucks and associated trailers. These flaps are generally intended to reduce the volume of debris and rainwater that is thrown from the rotating tires of a truck while the truck moves along a roadway in inclement weather. Rain flaps have to some extent reduced the hazards posed by flying debris and rainwater directly behind such a vehicle, however, the flaps in turn have a disadvantageous tendency to deflect substantial amounts of rainwater, snow, sleet, ice and other debris outwardly from the sides of the truck. Such side sprays pose a significant hazard to other motorists by obstructing the vision path of other motorists in the vicinity of the truck, including those following the truck or those passing the truck in either direction. Driving in the vicinity of a truck during inclement weather therefore, often means that the drivers of such other vehicles will be temporarily blinded. The spray in some circumstances may extend fifteen to twenty feet out to each side, making the truck a continuously moving barrier to safe vision.
Several arrangements have been proposed to reduce the spray caused by such vehicles, such as that described in U.S. Pat. No. 3,006,658 to Wenham et al. Wenham discloses a bracket that follows the contour of the tires of the truck and guards against throwing material out to the side. However, the configuration of Wenham et al. causes substantial air turbulence around the leading edge of the bracket. Accordingly, this has not proven to be fully satisfactory since the air currents around the outside edges of the flaps still tend to throw materials and debris out to the side.
U.S. Pat. No. 3,721,459 to Lea discloses a shield extending around the upper portion of the tire to reduce side spray. However, there is no provision to reduce air flow across the forward surface of the flap or reduce the turbulence at the edges thereof which tend to cause side spray. Accordingly, Lea has not proven satisfactory.
U.S. Pat. No. 3,830,520 to Kelly and U.S. Pat. No. 3,877,722 to Conner propose mud flap stiffeners to prevent the flap from sailing or flying away from the wheel and enhancing the performance of the flap. However, there is no provision in these arrangements for controlling or directing the air flow across the forward side of the flaps. Further, the flaps in each of these arrangements create vortices which in conjunction with the lateral air currents across the surface of the flaps produce side spray.
U.S. Pat. No. 3,027,178 to Eaves and U.S. Pat. No. 4,382,606 to Lightle, et al. have proposed improved designs for the flaps. Eaves discloses a molded plastic flap with flanges and ribs to make the flap more rigid to avoid sailing. Lightle et al. discloses a mud flap with flow-directing ribs on the surface to catch the water and direct it down the surface of the flap. The flap also includes vertically extending side flanges to confine the water on the surface and prevent it from escaping around the side edges of the flap. These flaps, however, tend to allow some water to escape around the sides of the flap.
Accordingly, it is an object of the present invention to provide an apparatus which substantially reduces the side spray from flaps and avoids the disadvantages of the prior art as discussed above.